New findings published in the journal Obesity reveal that women who are drinking alcohol may also be more likely to eat more as alcohol exposure sensitizes the brain's response to food aromas, increasing caloric intake.

"The brain, absent contributions from the gut, can play a vital role in regulating food intake. Our study found that alcohol exposure can both increase the brain's sensitivity to external food cues, like aromas, and result in greater food consumption," said lead study author William J. A. Eiler II, PhD, of the Indiana University School of Medicine's Departments of Medicine and Neurology, in a news release. "Many alcoholic beverages already include empty calories, and when you combine those calories with the aperitif effect, it can lead to energy imbalance and possibly weight gain."

For the study, researchers examined 35 non-vegetarian, non-smoking women, all at a normal weight. They tested the direct effects of alcohol on the brain, circumventing the digestive system by exposing participants to intravenously administered alcohol at one study visit and then to a saline placebo in another study visit prior to eating. Brain responses to food and non-food aromas were also measured via blood oxygenation level development (BOLD) response via fMRI scans following imaging. Participants could also chose between pasta with Italian meat sauce and beef and noodles for lunch.

When participants received intravenous alcohol, they ate more food at lunch on average when compared to participants who were given the placebo. However, certain individual differences existed, including one-third of participants who ate less after alcohol exposure as compared to placebo-participants.

Furthermore, findings revealed areas of the brain that are key to certain metabolic processes, including the hypothalamus, with certain food odors compared to non-food odors, after alcohol infusion vs. saline. With this, researchers concluded that the hypothalamus may hold a role in mediating the impact of alcohol exposure when it comes to certain food cues that contribute to the aperitif phenomenon.

"This research helps us to further understand the neural pathways involved in the relationship between food consumption and alcohol," said Martin Binks, PhD, FTOS, TOS Secretary Treasurer and Associate Professor of Nutrition Sciences at Texas Tech University. "Often, the relationship between alcohol on eating is oversimplified; this study unveils a potentially more complex process in need of further study."